I feel I need to reiterate how Pax works, from someone who goes every year.
There isn't even a venue for Nintendo to make an announcement. There's no big hall where the different game companies go to give presentations. There's just a show floor, and Nintendo's booth is usually smaller than some of the average third parties, even. Even last year's Nintendo booth, which was one of the largest they've ever had, with lots of Smash Bros setups, was smaller than Ubisoft's. They also never participate in the (extremely popular) pin trading community, despite Sony, Microsoft, and practically all the big third parties doing so.
Let me just give a list of companies that have more floor space than Nintendo this year: Sony, Microsoft, Ubisoft, 2K Games, Capcom, Deep Silver, Bandai Namco. The list goes on. You think Nintendo couldn't get more floor space than 2K Games? Of course they could. But they choose not to.
All this to say, Pax is not very important to Nintendo. They show up, but it often feels more like an obligation than a genuine interest in reaching out to fans.